Water concentration, Cw, & the mean effective diffusion coefficient of water, Dw, were measured by vacuum hot extraction coupled with mass spectrometer evolved gas analysis (VHE). The study includes silica, soda & potassium-lime-silica, cordierite, & lamp bulb glasses of water concentrations between 0.017 & 0.17 mol H2O/I(122 & 1159 wt.ppm) as well as cordierite single crystals. Cw was obtained by integration of the VHE water degassing rate. For powdered samples of silica, soda-lime-silica & cordierite glass with water concentrations between 0.033 & 0.15 mol/I, VHE results confirm IR spectroscopy within 5 to 15% accuracy. The applied methods & samples allowed the measuring of Dw within 10-9 & 10-13 cm2s-1. Calculated values of Dw for soda-lime-silica glasses agree with literature data & values obtained by IR spectroscopy within a factor of 2 to 4.
